/*
** $Id: llimits.h $
** Limits, basic types, and some other 'installation-dependent' definitions
** See Copyright Notice in lua.h
*/

#ifndef llimits_h
#define llimits_h

#include <limits.h>
#include <stddef.h>

#include "lua.h"

/*
** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count
** the total memory used by Lua (in bytes). Usually, 'size_t' and
** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines.
*/
#if defined(LUAI_MEM) /* { external definitions? */
typedef LUAI_UMEM lu_mem;
typedef LUAI_MEM l_mem;
#elif LUAI_IS32INT      /* }{ */
typedef size_t lu_mem;
typedef ptrdiff_t l_mem;
#else /* 16-bit ints */ /* }{ */
typedef unsigned long lu_mem;
typedef long l_mem;
#endif                  /* } */

/* chars used as small naturals (so that 'char' is reserved for characters) */
typedef unsigned char lu_byte;
typedef signed char ls_byte;

/* maximum value for size_t */
#define MAX_SIZET     ((size_t)(~(size_t)0))

/* maximum size visible for Lua (must be representable in a lua_Integer) */
#define MAX_SIZE      (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET : (size_t)(LUA_MAXINTEGER))

#define MAX_LUMEM     ((lu_mem)(~(lu_mem)0))

#define MAX_LMEM      ((l_mem)(MAX_LUMEM >> 1))

#define MAX_INT       INT_MAX /* maximum value of an int */

/*
** floor of the log2 of the maximum signed value for integral type 't'.
** (That is, maximum 'n' such that '2^n' fits in the given signed type.)
*/
#define log2maxs(t)   (sizeof(t) * 8 - 2)

/*
** test whether an unsigned value is a power of 2 (or zero)
*/
#define ispow2(x)     (((x) & ((x)-1)) == 0)

/* number of chars of a literal string without the ending \0 */
#define LL(x)         (sizeof(x) / sizeof(char) - 1)

/*
** conversion of pointer to unsigned integer:
** this is for hashing only; there is no problem if the integer
** cannot hold the whole pointer value
*/
#define point2uint(p) ((unsigned int)((size_t)(p)&UINT_MAX))

/* types of 'usual argument conversions' for lua_Number and lua_Integer */
typedef LUAI_UACNUMBER l_uacNumber;
typedef LUAI_UACINT l_uacInt;

/*
** Internal assertions for in-house debugging
*/
#if defined LUAI_ASSERT
#undef NDEBUG
#include <assert.h>
#define lua_assert(c) luaport_assert(c)
#endif

#if defined(lua_assert)
#define check_exp(c, e)   (lua_assert(c), (e))
/* to avoid problems with conditions too long */
#define lua_longassert(c) ((c) ? (void)0 : lua_assert(0))
#else
#define lua_assert(c)     ((void)0)
#define check_exp(c, e)   (e)
#define lua_longassert(c) ((void)0)
#endif

/*
** assertion for checking API calls
*/
#if !defined(luai_apicheck)
#define luai_apicheck(l, e) ((void)l, lua_assert(e))
#endif

#define api_check(l, e, msg) luai_apicheck(l, (e) && msg)

/* macro to avoid warnings about unused variables */
#if !defined(UNUSED)
#define UNUSED(x) ((void)(x))
#endif

/* type casts (a macro highlights casts in the code) */
#define cast(t, exp)  ((t)(exp))

#define cast_void(i)  cast(void, (i))
#define cast_voidp(i) cast(void *, (i))
#define cast_num(i)   cast(lua_Number, (i))
#define cast_int(i)   cast(int, (i))
#define cast_uint(i)  cast(unsigned int, (i))
#define cast_byte(i)  cast(lu_byte, (i))
#define cast_uchar(i) cast(unsigned char, (i))
#define cast_char(i)  cast(char, (i))
#define cast_charp(i) cast(char *, (i))
#define cast_sizet(i) cast(size_t, (i))

/* cast a signed lua_Integer to lua_Unsigned */
#if !defined(l_castS2U)
#define l_castS2U(i) ((lua_Unsigned)(i))
#endif

/*
** cast a lua_Unsigned to a signed lua_Integer; this cast is
** not strict ISO C, but two-complement architectures should
** work fine.
*/
#if !defined(l_castU2S)
#define l_castU2S(i) ((lua_Integer)(i))
#endif

/*
** non-return type
*/
#if !defined(l_noret)

#if defined(__GNUC__)
#define l_noret void __attribute__((noreturn))
#elif defined(_MSC_VER) && _MSC_VER >= 1200
#define l_noret void __declspec(noreturn)
#else
#define l_noret void
#endif

#endif

/*
** Inline functions
*/
#if !defined(LUA_USE_C89)
#define l_inline inline
#elif defined(__GNUC__)
#define l_inline __inline__
#else
#define l_inline /* empty */
#endif

#define l_sinline static l_inline

/*
** type for virtual-machine instructions;
** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)
*/
#if LUAI_IS32INT
typedef unsigned int l_uint32;
#else
typedef unsigned long l_uint32;
#endif

typedef l_uint32 Instruction;

/*
** Maximum length for short strings, that is, strings that are
** internalized. (Cannot be smaller than reserved words or tags for
** metamethods, as these strings must be internalized;
** #("function") = 8, #("__newindex") = 10.)
*/
#if !defined(LUAI_MAXSHORTLEN)
#define LUAI_MAXSHORTLEN 40
#endif

/*
** Initial size for the string table (must be power of 2).
** The Lua core alone registers ~50 strings (reserved words +
** metaevent keys + a few others). Libraries would typically add
** a few dozens more.
*/
#if !defined(MINSTRTABSIZE)
#define MINSTRTABSIZE 128
#endif

/*
** Size of cache for strings in the API. 'N' is the number of
** sets (better be a prime) and "M" is the size of each set (M == 1
** makes a direct cache.)
*/
#if !defined(STRCACHE_N)
#define STRCACHE_N 53
#define STRCACHE_M 2
#endif

/* minimum size for string buffer */
#if !defined(LUA_MINBUFFER)
#define LUA_MINBUFFER 32
#endif

/*
** Maximum depth for nested C calls, syntactical nested non-terminals,
** and other features implemented through recursion in C. (Value must
** fit in a 16-bit unsigned integer. It must also be compatible with
** the size of the C stack.)
*/
#if !defined(LUAI_MAXCCALLS)
#define LUAI_MAXCCALLS 200
#endif

/*
** macros that are executed whenever program enters the Lua core
** ('lua_lock') and leaves the core ('lua_unlock')
*/
#if !defined(lua_lock)
#define lua_lock(L)   ((void)0)
#define lua_unlock(L) ((void)0)
#endif

/*
** macro executed during Lua functions at points where the
** function can yield.
*/
#if !defined(luai_threadyield)
#define luai_threadyield(L) \
    {                       \
        lua_unlock(L);      \
        lua_lock(L);        \
    }
#endif

/*
** these macros allow user-specific actions when a thread is
** created/deleted/resumed/yielded.
*/
#if !defined(luai_userstateopen)
#define luai_userstateopen(L) ((void)L)
#endif

#if !defined(luai_userstateclose)
#define luai_userstateclose(L) ((void)L)
#endif

#if !defined(luai_userstatethread)
#define luai_userstatethread(L, L1) ((void)L)
#endif

#if !defined(luai_userstatefree)
#define luai_userstatefree(L, L1) ((void)L)
#endif

#if !defined(luai_userstateresume)
#define luai_userstateresume(L, n) ((void)L)
#endif

#if !defined(luai_userstateyield)
#define luai_userstateyield(L, n) ((void)L)
#endif

/*
** The luai_num* macros define the primitive operations over numbers.
*/

/* floor division (defined as 'floor(a/b)') */
#if !defined(luai_numidiv)
#define luai_numidiv(L, a, b) ((void)L, l_floor(luai_numdiv(L, a, b)))
#endif

/* float division */
#if !defined(luai_numdiv)
#define luai_numdiv(L, a, b) ((a) / (b))
#endif

/*
** modulo: defined as 'a - floor(a/b)*b'; the direct computation
** using this definition has several problems with rounding errors,
** so it is better to use 'fmod'. 'fmod' gives the result of
** 'a - trunc(a/b)*b', and therefore must be corrected when
** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a
** non-integer negative result: non-integer result is equivalent to
** a non-zero remainder 'm'; negative result is equivalent to 'a' and
** 'b' with different signs, or 'm' and 'b' with different signs
** (as the result 'm' of 'fmod' has the same sign of 'a').
*/
#if !defined(luai_nummod)
#define luai_nummod(L, a, b, m)                         \
    {                                                   \
        (void)L;                                        \
        (m) = l_mathop(fmod)(a, b);                     \
        if (((m) > 0) ? (b) < 0 : ((m) < 0 && (b) > 0)) \
            (m) += (b);                                 \
    }
#endif

/* exponentiation */
#if !defined(luai_numpow)
#define luai_numpow(L, a, b) \
    ((void)L, (b == 2) ? (a) * (a) : l_mathop(pow)(a, b))
#endif

/* the others are quite standard operations */
#if !defined(luai_numadd)
#define luai_numadd(L, a, b) ((a) + (b))
#define luai_numsub(L, a, b) ((a) - (b))
#define luai_nummul(L, a, b) ((a) * (b))
#define luai_numunm(L, a)    (-(a))
#define luai_numeq(a, b)     ((a) == (b))
#define luai_numlt(a, b)     ((a) < (b))
#define luai_numle(a, b)     ((a) <= (b))
#define luai_numgt(a, b)     ((a) > (b))
#define luai_numge(a, b)     ((a) >= (b))
#define luai_numisnan(a)     (!luai_numeq((a), (a)))
#endif

/*
** macro to control inclusion of some hard tests on stack reallocation
*/
#if !defined(HARDSTACKTESTS)
#define condmovestack(L, pre, pos) ((void)0)
#else
/* realloc stack keeping its size */
#define condmovestack(L, pre, pos)      \
    {                                   \
        int sz_ = stacksize(L);         \
        pre;                            \
        luaD_reallocstack((L), sz_, 0); \
        pos;                            \
    }
#endif

#if !defined(HARDMEMTESTS)
#define condchangemem(L, pre, pos) ((void)0)
#else
#define condchangemem(L, pre, pos) \
    {                              \
        if (gcrunning(G(L))) {     \
            pre;                   \
            luaC_fullgc(L, 0);     \
            pos;                   \
        }                          \
    }
#endif

#endif
